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Hydrophobic zinc(II) phthalocyanine-type derivatives, solubilized in polymeric micelles (PMs), provide a befitting group of so-called nanophotosensitizers, suitable for a variety of photodynamic therapy (PDT) protocols. The factors that influence the success of such products in PDT are the location of the active cargo in the PMs and the nanocarrier-enhanced ability to safely interact with biological systems and fulfill their therapeutic functions. Therefore, the aim of this work was to determine the solubilization loci of three phthalocyanines of varying hydrophobicity, i.e., zinc(II) phthalocyanine (ZnPc), along with its tetrasulfonic acid (ZnPc-sulfo4) and perfluorinated (ZnPcF16) derivatives, loaded in polymeric micelles of methoxy poly(ethylene oxide)-b-poly(l-lactide) (mPEG-b-PLLA), by means of 1H nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) combined with ion sputtering. Furthermore, the microenvironment influence upon the chemical and physical status of the solubilized...

We report activation of a photodynamic therapy photosensitizer, zinc phthalocyanine, by Forster resonant energy transfer (FRET) from two-photon absorption excited CdSexS1–x/ZnS quantum dots coencapsulated in multifunctional biocompatible polymer nanocapsules. Polymer nanocapsules (100 nm size) were prepared via solvent/evaporation method using Poloxamer 403 as the polymer component, Cremophor EL as the surfactant and mixture of silicone oil with hydrogenated caprylyl olive oil esters as the oil phase. UV–vis–NIR absorption and multiphoton fluorescence studies confirmed successful coencapsulation of both components of the FRET system. The energy transfer between the quantum dots as donors and Zn phthalocyanine molecules as acceptors was studied using steady-state photoluminescence and time-correlated single photon counting techniques. The changes in the lifetime of the QDs emission indicate that the excitation of ZnPc occurs not only through reabsorption but also through FRET. The generation of the reactiv...

Highly fluorescent quantum dots (QDs)-loaded nanocapsules, intended for fluorescent cell imaging, were prepared via an emulsification/solvent-evaporation method. CdSe/ZnS core/shell quantum dots were applied as cargo; Poloxamer 403 as the polymer component; Cremophor EL as the nonionic surfactant; and mineral oil, oleic acid, or silicone oil were applied as the oil phases. Transmission electron microscopy, atomic force microscopy, dynamic light scattering, and zeta potential measurements were used to characterize the novel QDs-labeled nanoparticles by particle size, distribution, and morphology, as well as by ζ-potential and physical stability. The fabricated long-lasting nanocapsules exhibit good luminescence properties upon both one-photon and two-photon excitation. The potential of the encapsulated QDs for fluorescent imaging was evaluated in cytotoxicity studies as well as in imaging of intracellular localization, accumulation, and distribution of QDs delivered to well-characterized human cancer cell lines--doxorubicin-sensitive breast (MCF-7/WT) and alveolar basal epithelial (A549)--as well as on normal human umbilical vein endothelial (HUVEC) cells, as investigated by confocal laser scanning microscopy (CLSM). The colloidal CdSe/ZnS-loaded nanocapsules are shown to exhibit strong two-photon-induced luminescence upon excitation in the NIR optical transmission window spectral range, making them ideal markers for bioimaging application. The total two-photon cross section of a single nanocapsule was determined to be about 4.1 × 10(6) GM at 800 nm.

A systematic study concerning adsorption and aggregation of chemodegradable, diastereomerically pure sodium cis- and trans-(2-n-alkyl-1,3-dioxan-5-yl) sulfates (alkyl: n-C9H19 and n-C11H23) in the system consisting of n-heptane in contact with aqueous 0.2 M NaCl at 31 °C has been undertaken. The role of the six-membered 1,3-dioxane ring has been discussed in terms of comparison between studied surfactants and “classical” sodium decyl and dodecyl sulfates. Surface parameters of compounds under study at the oil−water interface, i.e., surface tension reduction (π), surface excess concentration (Γ), surface area demand per molecule (A), critical micelle concentration (cmc), standard free energy of adsorption (ΔGoads), and of micellization (ΔGocmc), show differences due to the alkyl chain length and to the hydrophilic, i.e., sulfate group configuration at the C-5 atom of the 1,3-dioxane ring. The cmc, ΔGoads, and ΔGocmc values are lower for the trans isomers than for the cis ones, whereas the effectiveness of...

Dehydrobromination reactions of para-substituted 2-phenylethyl bromides, i.e., p-Y-C 6 H 4 CH 2 CH 2 Br (Y=NO 2 , Cl, H, OCH 3 ) have been examined in aqueous micelles of the functional surfactant N,N-dimethyl-N-(2-hydroxyethyl)-n-hexadexylammonium bromide (1) in the presence of sodium hydroxide. The kinetic experiments have been performed for a partially deprotonated nucleophilic head group. The variation of the overall first-order rate constant, k ψ , with concentration of 1 can be fitted to equations describing the micellar effect on the bimolecular reaction in the cationic micelle as well as acid-base and ion-exchange equilibria

Reactions d'elimination β realisees sur le α-bromo benzenepropionate d'ethyle et le α-bromo α-methyl benzenepropionate de methyle

L'etude est faite pour les composes C 6 H 5 CH 2 CH 2 X avec X=Br, p-CH 3 C 6 H 4 SO 3 , + S(CH 3 ) 2 , + N(CH 3 ) 3 . On applique les criteres TDKIE aux eliminations E2 (TDKIE= influence de la temperature sur l'effet isotopique cinetique H/D)

The rate constants for reactions of OH{sup {minus}} with para-substituted 2-phenylethyl bromides, i.e., p-X-C{sub 6}H{sub 4}CH{sub 2}CH{sub 2}Br (X = NO{sub 2}, Cl, H), were determined under micellar (k{sub {psi}}) and nonmicellar (k{sub w}{prime}) conditions by using hexadecyltrimethylammonium bromide ((CTA)Br) and hydroxide ((CTA)OH) as the micellar agents. The results can be explained with the pseudophase ion-exchange model. The evaluated second-order rate constants in micelles are greater than the second-order rate constants in water by factors of 3.4, 2.0, and 1.1 for X = NO{sub 2}, Cl, and H, respectively.